In which of the following situations would the use of a QDOT be appropriate? Regina dies and is survived by her husband, Liam, who becomes a U.S. citizen two months after Regina's death Dean dies and is survived by his wife, Tina, who is not a U.S. citizen Sawyer dies and does not have a surviving spouse but has a significant other, who is not a U.S. citizen Franz, who is not a U.S. citizen, dies and is survived by his wife, Adel, who is a U.S. citizen